In a complaint filed in federal court on Tuesday, the Gila River Indian Community and Gila River Health Care Corporation, claim the department owes them for health care provided to veterans going back to March 2010.

Under President Barack Obama's health care law, the VA must reimburse Indian tribes for health care services to veterans who seek care from tribal clinics or hospitals instead of a VA facility.

"Despite this plain and mandatory language directing the Department of Veterans Affairs to reimburse Indian tribes and tribal organizations for health care services provided to veterans, the VA refuses to do so unless Indian tribes and tribal organizations agree to conditions well beyond the plain language of the law and which reduce the reimbursements that Indian tribes are entitled to under the law," the complaint says.

Those conditions include limiting reimbursements to direct care services only and excluding purchased or referred care; excluding reimbursement for non-Native veterans, such as non-Native spouses of tribal members; and requiring the Gila River Health Care Corporation to "submit disputes with the VA for resolution by the VA's own contracting officer."

The Gila River Health Care Corporation operates a hospital in Sacaton, Ariz., a small reservation town about 40 miles south of Phoenix. The hospital has seen an increase in veterans in recent years because patients are "unable to secure timely appointments through the VA" and because "the Phoenix VA in particular has been plagued by well-publicized health care scandals alleging poor quality of care and long waits for appointments," the lawsuit states.

Gila River officials say they have tried for years to negotiate with the VA over these issues, and even sent a delegation to meet with department officials in Washington, D.C.

In 2013, a lawyer for the department "confirmed that VA's position will not change unless it is required to change by the Department of Justice or unless the Community sued the federal government and prevailed in court," the lawsuit states.

"All Community efforts have been rejected, and from March 23, 2010, through the date of this complaint, VA has provided no reimbursements to GRHC," the lawsuit says.

In addition to an award of an order for reimbursement, the tribe wants the court to declare that the VA is violating the Affordable Care Act by "conditioning reimbursements on a separate agreement by VA," and by limiting reimbursements to Native American veterans and direct care services only.

It's unclear from the lawsuit how much the VA allegedly owes the Gila River Indian Community. Attorneys with the tribe's Office of the General Counsel did not immediately respond to an email on Tuesday.

The Department of Veterans Affairs also did not respond to a request for comment.

Last week, the VA announced the proposed removal of three senior officials at the Phoenix VA Health Care System.

After a whistleblower and media investigations revealed shocking problems at the Phoenix VA in 2014, an Office of Inspector General report confirmed that some 40 patients had died while on a wait list for care between April 2013 through April 2014.

The report also identified numerous cases of "unacceptable and troubling lapses in follow-up, coordination, quality, and continuity of care" at the Phoenix facility.